Synthesis, crystal structure and photoluminescence properties of novel far-red-emitting SrLaZnSbO6:Mn4+ double-perovskite phosphors for plant cultivation LEDs

In this work, we demonstrated novel Mn 4+ -activated double-perovskite SrLaZnSbO 6 (SLZS) far-red-emitting phosphors for plant cultivation LED lighting. These SLZS:Mn 4+ far-red-emitting phosphors doped with various Mn 4+ concentrations were successfully prepared by using a traditional high-temperature solid-state reaction route. The phase purity, crystal structure, photoluminescence properties, decay lifetimes, CIE chromaticity coordinates and temperature-dependent spectra of as-prepared samples were systematically studied. The SLZS:Mn 4+ phosphors showed an intense far-red emission band in the 650−800 nm spectral region with a maximum at 706 nm under 364 nm excitation, which was due to the 2 E g → 4 A 2g transition of Mn 4+ ions. The optimal doping concentration of Mn 4+ ions in SLZS:Mn 4+ phosphors was found to be 0.5 mol%. And the CIE chromaticity coordinates of SLZS:0.5 %Mn 4+ phosphors were calculated to be (0.7276, 0.2724), which were located in the far-red region. The emission spectrum of SLZS:Mn 4+ phosphors could match well with the absorption band of phytochrome P FR . All of these results demonstrate that SLZS:Mn 4+ phosphors have a huge potential application in indoor plant cultivation.